Extensible support



July 13, 1965 HENDRY 3,194,593

EXTENSIBLE SUPPORT Filed Oct. 5, 1962 WET l United States Patent '0 3,194,593 EXTENSIBLE SUPPORT Robert G. Hendry, 41 Kaymar, Box 335, RR. 1, Ottawa, Ontario, Canada Filed Oct. 3, 1962, Ser. No. 228,083 2 Claims. (Cl. 28758) This invention relates to a variable length member particularly suitable as a support for furniture or the like.

Extensible supports having locking devices are known but those available are unsatisfactory, particularly in furniture, in that the locking devices are not concealed and thus present an objectionable appearance. Furthermore, many known adjustable supports are unsatisfactory because they are not designed to provide positive locking of the two members in an extended position to support the weight of a table, for example, and the additional load that may be placed thereon.

The principal object of the present invention is to provide an adjustable support having a concealed locking device whereby the support may be positively locked to provide a load bearing member in an extended position.

A further object is to provide a variable length support having locking means which is relatively easily manipulated.

The above objects may be obtained and the foregoing disadvantages overcome by use of the instant invention.

Accordingly the present invention consists of an extensible support including a first and second rigid elongated member, said first member having a longitudinal bore therein, said second rigid elongated member adapted to slide longitudinally in the bore of said first member, the walls of said bore defining a transverse slot including an inwardly bevelled edge, locking means on said second member resiliently biased to urge said means radially outwardly therefrom to engage said transverse slot thereby locking said first member to said second member at a predetermined extended position, said locking means co-operating with said slot to provide cam action on the bevelled edge thereof, to release said locking means as said second member is rotated relative to said first member.

Additional objects and features of the invention will become apparent from the following description and with reference to the accompanying drawing in which:

FIG. 1 is a partial sectional elevational view of a furniture leg in an extended position;

FIG. 2 is a cross sectional view along the line 2-2 of the locking means of FIG. 1;

FIG. 3 is a transverse cross sectional view along the line 33 of FIG. 2;

FIG. 4 is a tranverse' sectional view along the line 44 of FIG. 2;

FIG. 5 is a perspective view of the guide spring; and

FIG. 6 is an alternate form wherein the support member is square in cross-section.

Referring now in detail to the drawing an extensible member, shown generally at 20 in FIG. 1, consists of an elongated rigid first member 1 having a bore 1' therein, and an elongated rigid second member 2 both made of wood or other suitable material. A cylindrical liner 3 is fitted within the bore 1' of the first member 1. A cylindrical sleeve 4 is secured to the upper end of the second member 2. The cylindrical sleeve 4 is adapted to fit snugly in and slide freely in the cylindrical liner 3.

An arcuate slot 13 having inwardly bevelled edges 17 as shown in FIG. 4 is provided in the cylindrical liner 3 to co-operate with a pin 11 in a bore 18 in the second member 2. The pin is resiliently biased by helical spring 15. A sleeve 14- surrounds the pin 11 to reduce friction and wear. All the above-mentioned elements except the "ice first member 1 and the second member 2 are made of metal. The pin 11 is provided with a shoulder 12 to regulate the distance said pin will protrude through a hole 16 in cylindrical sleeve 4.

A guide spring 6 shown in FIGS. 3 and 5 is attached to the second member 2 by means of a retaining screw 9. One end of the guide spring is secured in a slot 7 in a raised portion 8 (the other end of the guide spring 6 being free to rotate through an arc of about extends through an arcuate slot 5 in cylindrical sleeve 4 and engages a slot 19 extending longitudinally in cylindrical liner 3.

The extensible member 2 may be provided with ferrule 26 and any conventional attaching means such as stud 19.

In operation the cylindrical sleeve 4 of the second member 2 is adapted to fit snugly in and slide freely in cylinrical liner 3 of the hollow first member 1. In the extended position pin 11 co-operates with arcuate slot 13 to lock the two members in such position. To release the locking pin 11, the second member 2 is rotated relative to the first member 1 thus causing the end of pin 11 to engage one of the inwardly beveled edges 17 of the arcuate slot 13. The bevelled edge 17 of the arcuate slot 13 engaging pin 11 in this manner depresses pin 11 and compresses helical spring 15 and a slight downward movement of the first member 1 moves the pin 11 out of align ment with the arcuate slot 13 allowing the second member 2 to slide into the cylindrical liner 3 of the first member 1.

Rotating the second member 2 in either direction to release the locking pin 11 also causes the guide spring 6 to be bent. Then as the second member 2 is slid into the first member 1, the free end of the guide spring 6 follows the longitudinal slot 10 in the cylindrical liner. The guide spring 6 on straightening out causes the second member to rotate and thus return to the position held before the rotary force was applied. To ensure that the end of pin 11 properly engages bevelled edge 17 pin 11 has been provided with shoulders 12 to regulate the distance said pin 11 will protrude through hole 16 in cylindrical sleeve 4.

When the extensible member is again extended the second member 2 is slid out of the first member until pin 11 registers with arcuate slot 13 and helical spring 15 urges the end of pin 11 into slot 13.

As the extensible member is again extended, one end of guide spring 6 follows the longitudinal slot 10 in the cylindrical liner 3 thus ensuring that pin 11 returns to a radial position in line with slot 13 and will engage said slot.

Alternatively in order to provide for the use of square legs on a piece of furniture, the device may be constructed as shown in FIG. 6.

Referring now in detail to the drawing an extensible member shown in FIG. 6 consists of an elongated rigid first member 1" adapted to receive a square tubular liner 3 and a rigid second member 2' having a quare cross section throughout its length and cylindrically shaped portion 22 adjacent one end thereof. A cylindrical sleeve 4 is adapted to fit on the cylindrical end 22 and includes a spring activated pin 11' similar to the pin 11 described previously with respect to FIGS. 1 to 5.

A square sleeve 23 having a slot 24 in a side thereof is adapted to fit snugly and slide freely within liner 3' and is rotatably mounted over the cylindrical sleeve 4' so that pin 11' will protrude through slot 24 to engage a slot 13' in the tubular liner 3.

The rigid second member 2' is resiliently biased in a normal rest position by a spring 6' secured by a screw 9' and slot 7 in the same manner as guide spring 6 shown in FIGS. 1 to 5 and described above. One end of the 3 spring 6 is secured to the sleeve 23 by inserting it through hole 25 across a depression between the holes 25 in the sleeve 23 and back through the other hole 25. v In operation, pin 11' in cylindrical sleeve 4' extends through slot 24 in square sleeve 23 to engage slot 13 of square liner 3. The square second member 2' is thus held in place in an extended position in liner 3' by pin 11';

To disengage pin 11 second member 2 is rotated relative to first member 1" thus causing the end of pin 11' to engage one of the inwardly bevelled edges 17' of the slot 13. The bevelled edge 17' of the slot engaging the pin 11' in this manner depresses pin 11 and a slight downward movement of the first member 1" moves the pin 11' out of alignment with the slot 13'. The square second member 2 is then aligned with the square liner 3' to allow the second member 2 to slide into the first member 1".

The spring 6' assists in aligning second member 2 with the liner 3'.

Whenthe extensible member is again extended the second member 2 is slid out of the first member until pin 11 registers with slot 13'.

Although the embodiment herein described is con structed of wood and metal combined, it is understood that other structural materials could easily be substituted without departing from the spirit of the invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: a

I claim:

1. An extensible support including a first and second rigid elongated member, said first member having a longitudinal bore therein, a cylindrical liner in said bore of said first member, a longitudinal slot in said cylindrical liner, said cylindrical liner including a transverse slot having an inwardly bevelled edge, said second rigid elongated member being adapted to slide longitudinally in said cylindrical liner, a spring means for attaching said spring to said second member, and locking means on said second member resiliently biased to urge said means radially outwardly therefrom to engage said transverse slot of said cylindrical liner of said first member thereby locking said first member to said second member at a predetermined extended position, said locking means cooperating with said transverse slot, on the bevelled edge thereof, to release said locking means as aid second member is rotated relative to said first member, said longitudinal slot in said cylindrical liner co-operating with one end of said spring, to bias said second member relative to said first member thereby'to return said locking means or" said second member to:a radial position in register with said arcuate slot in said first member.

2. An extensible support including a first and second rigid elongated member, said first member having a longitudinal bore therein; said second rigid elongated mem ber adapted to slide longitudinally in the bore of said first member, walls of said bore defining a slot including an inwardly bevelled edge, locking means on said second member resiliently biased to urge said means radially outwardly therefrom to engage said slot of said first member thereby locking said first member to said second member at a predetermined extended position, said locking means co-operating with the bevelled edge of said slot to thereby release said locking means as said second member is rotated relative tosaid first member, said bore in said first member having asquare cross section throughout its length adapted to receive a second member, of substantially square cross section having one cylindrical end and a square sleeve rotatablymounted on said cylindrical end of said second member, said square sleeve including a tranverse slot through which said locking means extends to engage said slot of said first member and wherein said square sleeve is resiliently biased relative to said second member by spring means'on said second member thereby aligning a side of said second member with a corresponding side of said square sleeve.

References Cited by the Examiner UNITED STATES PATENTS CARL W. TOMLIN, Primary Examiner. THOMAS P. CALLAGHAN, Examiner. 

1. AN EXTENSIBLE SUPPORT INCLUDING A FIRST AND SECOND RIGID ELONGATED MEMBER, SAID FIRST MEMBER HAVING A LONGITUDINAL BORE THEREIN, A CYLINDRICAL LINER IN SAID BORE OF SAID FIRST MEMBER, A LONGITUDINAL SLOT IN SAID CYLINDRICAL LINER, SAID CYLINDRICAL LINER INCLUDING A TRANSVERSE SLOT HAVING AN INWARDLY BEVELLED EDGE, SAID SECOND RIGID ELONGATED MEMBER BEING ADAPTED TO SLIDE LONGITUDINALLY IN SAID CYLINDRICAL LINER, A SPRING MEANS FOR ATTACHING SAID SPRING TO SAID SECOND MEMBER, AND LOCKING MEANS ON SAID SECOND MEMBER RESILIENTLY BIASED TO URGE SAID MEANS RADIALLY OUTWARDLY THEREFROM TO ENGAGE SAID TRANSVERSE SLOT OF SAID CYLINDRICAL LINER OF SAID FIRST MEMBER THEREBY LOCKING SAID FIRST MEMBER TO SAID SECOND MEMBER AT A PREDETERMINED EXTENDED POSITION, SAID LOCKING MEANS COOPERATING WITH SAID TRANSVERSE SLOT, ON THE BEVELLED EDGE THEREOF, TO RELEASE SAID LOCKING MEANS AS SAID SECOND MEMBER IS ROTATED RELATIVE TO SAID FIRST MEMBER, SAID LONGITUDINAL SLOT IN SAID CYLINDRICAL LINER CO-OPERATING WITH ONE END OF SAID SPRING, TO BIAS SAID SECOND MEMBER RELATIVE TO SAID FIRST MEMBER THEREBY TO RETURN SAID LOCKING MEANS TO SAID SECOND MEMBER TO A RADIAL POSITION IN REGISTER WITH SAID ARCUATE SLOT IN SAID FIRST MEMBER. 